Weight-loss surgery linked to higher risk of abusing alcohol

In a last ditch effort to lose weight, roughly 113,000 people subject themselves to bariatric surgeries such as stomach banding and gastric bypass every year in the United States. But some of those patients may be trading pounds for an alcohol problem, according to a new study presented today at the annual meeting of the American Society for Metabolic and Bariatric Surgery in San Diego, and published by the Journal of the American Medical Association.

Hints that bariatric operations could lead to subsequent alcohol abuse have been collecting over the past few years, as case reports and doctor anecdotes have filtered into discussions and scientific publications. But the new study, headed by Wendy C. King, assistant professor of epidemiology at University of Pittsburgh’s graduate school of public health, is the first to follow many patients treated at a number of institutions from pre-op through two years post-surgery.

In all, 1,945 adults were assessed from 2006 to 2011. Alcohol use disorder (AUD), meaning abuse and dependence, “significantly increased in the second post-operative year compared with the year prior to surgery or the first post-operative year,” the study says.

But that translates into about 2,000 more people with an alcohol use disorder, as King pointed out in the study, and in an interview. And even if a patient does not have AUD, she said, “one in eight patients in the second post-operative year reported typically drinking at least three drinks” when they drank. “That level can have implications for their weight loss, liver function, vitamin and mineral status so that is concerning….We don’t know the safe amount of booze after a [gastric] bypass.”

Almost the entire increase in AUD among bariatric surgery patients occurred in those receiving a type called Roux-en-Y gastric bypass. The biological mechanism at work has not yet been firmly established, but it likely rests in the differences between surgeries. In the Roux-en-Y procedure, doctors create a stomach pouch out of a small portion of the stomach and attach it directly to the small intestine.

Banding surgeries are restrictive -- they shrink the available space in the stomach so a person feels full after a small amount of food. Gastric bypass surgeries are both restrictive and malabsorptive, meaning they shrink space for food and change how its nutrients are absorbed in the small intestine.

As a result, gastric bypass patients feel alcohol’s effects faster, and for longer.

So the study’s findings, while important, aren’t surprising, explained Leslie Heinberg, the director of behavioral services for the Bariatric and Metabolic Institute of the Cleveland Clinic. Previous research has shown that male brains receive a more powerful reward from alcohol and among the study participants, the greatest risk for post-op alcohol abuse was in men.

Heinberg also pointed out one more prosaic possibility for an increase in AUD after surgery, one King acknowledged, too: When formerly obese people lose a lot of weight, they gain confidence, feel attractive, and may have more opportunity to socialize and drink.

That could explain why drinking and AUD was actually lower during the first year after surgery while patients were losing weight, then spiked during the second year. “It may be an unintended consequence of doing a heck of a lot better,” Heinberg, who was not associated with the study, suggested.

The findings should not dissuade anybody from a gastric bypass, Heinberg said, though both patients and doctors should weigh this information when considering risks and benefits of various surgeries.

Anita Courcoulas, professor of surgery and chief of minimally invasive bariatric and general surgery at the University of Pittsburgh Medical Center, who was a co-author of the study, stressed that “surgeons need to counsel patients” about the possibility of AUD. Importantly, she said in an email to msnbc.com, bariatric surgery patients should be monitored closely for long periods of time “for signs and symptoms of alcohol use disorders and should consider counseling after bariatric surgery.”